Cross-member construction is the most popular structure in foldable furniture. As shown in FIG. 1, a conventional cross-member construction is illustrated as a simple foldable stool or footstand. It comprises a first U-shape member 11 having two parallel stems 111, 112 respectively connected with two parallel stems 121, 122 of a second U-shape member 12 by means of cross-member construction, wherein a middle position of each of the stems 111, 112, 121, 122 provides a hole so that a connecting means 13, such as rivet or bolt and nut, is able to pivotally connect two corresponding stems 111 & 121 or 112 & 122 in such middle position by penetrating through the holes thereon. Accordingly, the two connecting stems 111 & 121 or 112 & 122 form a cross-member construction.
Such conventional cross-member construction enables the two stems 111 & 121 or 112 & 122 to selectively stretch apart from each other to form a X-shaped structure as shown in FIG. 1 or fold towards each other along the arrows shown in FIG. 1. It is well known that the conventional connecting means 13 can only pivotally connect two stems together but fails to provide any supporting to the two stems. In order to support the two U-shape members 11, 12 in position to form the X-shaped structure, at least a foldable supporting frame 14 must be mounted between the two stems. However, such supporting frame 14 can only limit the stretching distance between the two stems 111, 121. The weight of the sitter is almost fully supported by the rivets 13 connecting the stems and the supporting frame. In other words, such conventional cross-member construction fails to support heavy loading. Oppositely, the connecting means 13 of the conventional crossmember construction is easier to be damaged because it bears most of the loading stress.
Moreover, the user must also manually help to fold up the supporting frame 14 before folding up the foldable furniture. Sometimes, if the user fails to ensure the supporting fame 14 being fully stretched out, the cross-member construction will become very weak and may cause danger to the sitter. Besides, the manufacturer has to process excess step to install the supporting frame 14 that may unreasonably increase the manufacturing cost.